NAME¶
pfsstat - Show frame / image statistics
SYNOPSIS¶
pfsstat
DESCRIPTION¶
This command will show a short text statistic on each image in the pfs stream.
In the statistics you can find:
- File - name of the input file
- Width, Height - image dimensions
- Minimum - minimum luminance of an image(*), given in linear
- units (relative luminance in cd/m^2) and logarithmic units
- Maximum - maximum luminance of an image(*)
- Average - average luminance of an image(*)
- Mean - mean luminance of an image(*)
(*) Before min, max, average, median and dynamic range is computed, the
following processing is performed on an image: 1) negative and zero values are
replaced with the smallest positive value (to compute logarithms); 2) the
image is low-pass filtered. The low-pass filtering removes few very dark or
very bright pixels that can significantly influence estimation of the dynamic
range. The percentile, instead of a low-pass filter, is sometimes used for the
same purpose. However, a low-pass filter is preferred to the percentile in
pfstools since, taking into account the processing that is happening in the
human visual system, low-frequency band filter is more plausible.
Note: This command requires GNU Octave.
EXAMPLES¶
- pfsin memorial.hdr | pfsstat
Show statistics for the memorial image.
BUGS¶
Please report bugs and comments to Rafal Mantiuk <mantiuk@mpi-sb.mpg.de>.